A few good questions and answers on the whys of disc drop bars such as ...

The circumstances where a Colossal would make sense to me, at this stage in my riding and bike collecting, would be medium to long distance rides, particularly on moderate surfaces or chip seal, credit card touring, and foul-weather riding or mountain riding where the disc brakes make sense.

We were feeling alright last night and decided to take the Tandem up the climb that cooked our Avid BB5's nearly to the point of failure.

Havn't been back there since despite changing the brakes to the Bengal MB700T - I can't tell you how scarey it is to be on a very steep decent, two up on a tandem with brakes that are fading fast.

Did the new brakes hold up? ABSOLUTELY, I only needed about half power on them and we were fully under control, no burning smells and no blue rotors at the bottom. Last time we did this I had the levers pulled into the bars, smoke comming off the rotors and the bike was speeding up near the bottom. SCAREY.

I will mention we changed the rotors at the sametime to 203mm (from 160mm) which I am sure would be responsible for some of the improvement.

Very happy with the combo, we get a lot of twanging noises from the bigger rotors because any flex is multiplied which was far less of an issue on the smaller rotors.

Looks like Project 6.8 is dead then. No small dual front disks on that.

Looks like they have a 160 on the front. Hopefully the idea that 140 on the front of a road bike as a good specification will die off. As a manufacturer, you have to assume that a 100Kg+ guy is going to buy your bike to take into the mountains. So the brakes need to be specified to the heaviest person (the bike is specified for) in the most difficult terrain, with the most uneducated approach to braking. If it won't survive that easily, then it shouldn't be on the bike.

Also, as bad as it may look, I think the caliper should be on the front. This should provide better air cooling (especially for hydraulic) and to avoid stressing the quick release by the direction of the braking forces on axle.

Also, as bad as it may look, I think the caliper should be on the front. This should provide better air cooling (especially for hydraulic) and to avoid stressing the quick release by the direction of the braking forces on axle.

Looks like they have a 160 on the front. Hopefully the idea that 140 on the front of a road bike as a good specification will die off. As a manufacturer, you have to assume that a 100Kg+ guy is going to buy your bike to take into the mountains. So the brakes need to be specified to the heaviest person (the bike is specified for) in the most difficult terrain, with the most uneducated approach to braking. If it won't survive that easily, then it shouldn't be on the bike.

You seem to think you care more about the welfare of customers than the companies who are making the current line of bikes. Why not write to them directly and expresses your concerns? I very much doubt the trend towards smaller has gone untested by the designers (yes, maybe even with 100kg plus riders). In the meantime, maybe some basics may help you better understand why it is not just about “Oh, I can stop quickly”

It's About Control, Not PowerMany cyclists assume the biggest reason to switch to disc brakes is to gain stopping power. While hydraulic disc brakes on a road bike would almost certainly be more powerful than existing rim brakes, the bigger benefit is actually that cyclists would get control over the available power…….

MichaelB wrote:Typically the caliper is actually at the rear (on the font discs) as it allows a better path for cooling air to get to the inner core of the vented disc (air flows from centre to outside of disc).

Having a look at my setup on Celica, it is clear that the wheel shields the whole area anyway. However it still could be of benefit to have the caliper in front of the bike fork rather than air being shielded by it. Whether this and the braking forces going up at the axle has more value than the loss of aesthetics is another matter.

Last edited by Nobody on Fri Aug 31, 2012 2:04 pm, edited 2 times in total.

Have you cut your rear hose, and re-bled the line yet, any source on parts required/source of parts? Does it use DOT, or mineral oil? (I must admit I have a wiggle cart open with a parabox waiting for checkout in it!)

Nobody wrote: ..... However it still could be of benefit to have the caliper in front of the bike fork rather than air being shielded by it. Whether this and the braking forces going up at the axle has more value than the loss of aesthetics is another matter.

Although still hard to compare due to different camera angles and photo sizing, I'd say that the size is still the same. Since size was my primary interest, I won't be upgrading anytime soon for just the look and some grams.

JustJames wrote:Whenever an expert - and Zinn's expertise is, in fairness, considerable - announces that something can't be done, you can usually be sure that somebody is working on a way to do it.

You might be right. But disc brakes aren't a new technology. Any improvement in car/motorcycle brakes tends to come from bigger and heavier rotors and calipers.

"Thus, John, to get better performance from your disc brakes, get thicker cables and housings that won’t compress as much (or a hydraulic system), plus bigger rotors, bigger pads and stiffer calipers. You’ll have to suck up extra weight and aerodynamic drag as the costs of good braking."

I think it'll continue to be this way until someone develops an alternate material.

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